Impellers have a broad range of applications. For example, an impeller may be found in automobiles, appliances, or other fields for, for example, actively cooling or dissipating heat away from some heat generating components, climate control, thermal comfort, vehicle & machinery cooling systems, ventilation, fume extraction, winnowing (separating chaff of cereal grains), removing dust (vacuum cleaner), drying, providing draft for a fire, powering high speed boats with water jets. Impeller assembly may include the rotor (e.g., the impeller itself) that has an rotating or spinning arrangement of multiple vanes or blades (hereinafter blades) of various sizes attached to a hub to act on fluids through an output shaft of the power source. An impeller design may be subject to one or more requirements including, for example, structural strength or stress requirement, fatigue requirement, reliability requirement, flow rate requirement, noise requirement, operating efficiency requirement, cost, material selection requirement, etc. More specifically, the hub design in conventional impellers usually includes stiffeners to reinforce the structure of the impeller in one or more degrees of freedom. Nonetheless, conventional may transfer vibrations or fail to effectively suppress or reduce the vibrations between the blades or vanes of an impeller and one or more remaining components (e.g., the power source such as an electric motor) during the operation, ramping up of the power source from a complete stop to operational speed(s), or coasting down from operational speed(s) to a complete stop. Such vibrations are known to cause noises.
Thus, there exists a need for an improved impeller to achieve some or all of the requirements. Some embodiments are directed at improving one or more structural characteristics of the impeller while improving the noise performance or reducing or suppressing noise levels during operations of the impeller. Some of these embodiments further provide improved noise performance or reduced or suppressed noise levels during operations of the impeller while reducing or even eliminating any negative impact on the airflow requirement(s) or goal(s). In some of these embodiments, an improved impeller further reduce or even eliminate any negative impact on the strength, integrity, or reliability of the impeller assembly or one or more individual parts thereof.